Burgess agreed terms last week with Premiership club Bath, who have paid a fee believed to be around 500,000 Australian dollars (£270,000). He told his new club's website: "I'm very excited about the challenge."
Bath had been under the impression the Rugby Football Union would be responsible for paying for Burgess's release but the RFU distanced itself from the deal, conscious of the reaction of the other Premiership clubs.
